Dr. Black Aluminum Type B Magazine Base for Hi-Capa 5.1 GBB Pistols, Silver

If you run a Hi-Capa 5.1 for competition or serious skirmish, you know the stock plastic magazine base plate is the weakest link. It flexes under pressure, wears out from repeated drops onto hard surfaces, and does nothing to help you get that mag out of the gun faster.

The Dr. Black Type B base replaces that plastic with CNC-machined aluminum. The added weight changes how the magazine feels in your hand and, more importantly, how it behaves when you hit the floor during a reload. A heavier base means the mag drops cleaner and faster, which adds up over a stage. The machined edges also give you a better grip when you're wrestling a mag out under pressure.

This is a direct replacement for Tokyo Marui Hi-Capa 5.1 magazines. It does not fit other pistol platforms, and it does not convert a standard mag into a high-capacity version—it is just the bottom plate. You keep your existing magazine body and follower; you're only swapping the base.

Available in silver, machined from aluminum. The package includes one magazine base. Installation requires no tools beyond a small flat-head to pry off the old plastic base.